f2fs: introduce f2fs_msg to ease adding information prints

Introduced f2fs_msg function to differentiate f2fs specific messages in
the log. And, added few informative prints in the mount path, to convey
proper error in case of mount failure.
Signed-off-by: Namjae Jeon <namjae.jeon@samsung.com>
Signed-off-by: Amit Sahrawat <a.sahrawat@samsung.com>
Signed-off-by: Jaegeuk Kim <jaegeuk.kim@samsung.com>

fs/f2fs/f2fs.h

@@ -877,6 +877,8 @@ bool f2fs_empty_dir(struct inode *);
  * super.c
  */
 int f2fs_sync_fs(struct super_block *, int);
+extern __printf(3, 4)
+void f2fs_msg(struct super_block *, const char *, const char *, ...);
 
 /*
  * hash.c

fs/f2fs/super.c

@@ -53,6 +53,18 @@ static match_table_t f2fs_tokens = {
 	{Opt_err, NULL},
 };
 
+void f2fs_msg(struct super_block *sb, const char *level, const char *fmt, ...)
+{
+	struct va_format vaf;
+	va_list args;
+
+	va_start(args, fmt);
+	vaf.fmt = fmt;
+	vaf.va = &args;
+	printk("%sF2FS-fs (%s): %pV\n", level, sb->s_id, &vaf);
+	va_end(args);
+}
+
 static void init_once(void *foo)
 {
 	struct f2fs_inode_info *fi = (struct f2fs_inode_info *) foo;
@@ -247,7 +259,8 @@ static const struct export_operations f2fs_export_ops = {
 	.get_parent = f2fs_get_parent,
 };
 
-static int parse_options(struct f2fs_sb_info *sbi, char *options)
+static int parse_options(struct super_block *sb, struct f2fs_sb_info *sbi,
+				char *options)
 {
 	substring_t args[MAX_OPT_ARGS];
 	char *p;
@@ -286,7 +299,8 @@ static int parse_options(struct f2fs_sb_info *sbi, char *options)
 			break;
 #else
 		case Opt_nouser_xattr:
-			pr_info("nouser_xattr options not supported\n");
+			f2fs_msg(sb, KERN_INFO,
+				"nouser_xattr options not supported");
 			break;
 #endif
 #ifdef CONFIG_F2FS_FS_POSIX_ACL
@@ -295,7 +309,7 @@ static int parse_options(struct f2fs_sb_info *sbi, char *options)
 			break;
 #else
 		case Opt_noacl:
-			pr_info("noacl options not supported\n");
+			f2fs_msg(sb, KERN_INFO, "noacl options not supported");
 			break;
 #endif
 		case Opt_active_logs:
@@ -309,7 +323,8 @@ static int parse_options(struct f2fs_sb_info *sbi, char *options)
 			set_opt(sbi, DISABLE_EXT_IDENTIFY);
 			break;
 		default:
-			pr_err("Unrecognized mount option \"%s\" or missing value\n",
+			f2fs_msg(sb, KERN_ERR,
+				"Unrecognized mount option \"%s\" or missing value",
 				p);
 			return -EINVAL;
 		}
@@ -337,23 +352,36 @@ static loff_t max_file_size(unsigned bits)
 	return result;
 }
 
-static int sanity_check_raw_super(struct f2fs_super_block *raw_super)
+static int sanity_check_raw_super(struct super_block *sb,
+			struct f2fs_super_block *raw_super)
 {
 	unsigned int blocksize;
 
-	if (F2FS_SUPER_MAGIC != le32_to_cpu(raw_super->magic))
+	if (F2FS_SUPER_MAGIC != le32_to_cpu(raw_super->magic)) {
+		f2fs_msg(sb, KERN_INFO,
+			"Magic Mismatch, valid(0x%x) - read(0x%x)",
+			F2FS_SUPER_MAGIC, le32_to_cpu(raw_super->magic));
 		return 1;
+	}
 
 	/* Currently, support only 4KB block size */
 	blocksize = 1 << le32_to_cpu(raw_super->log_blocksize);
-	if (blocksize != PAGE_CACHE_SIZE)
+	if (blocksize != PAGE_CACHE_SIZE) {
+		f2fs_msg(sb, KERN_INFO,
+			"Invalid blocksize (%u), supports only 4KB\n",
+			blocksize);
 		return 1;
+	}
 	if (le32_to_cpu(raw_super->log_sectorsize) !=
-					F2FS_LOG_SECTOR_SIZE)
+					F2FS_LOG_SECTOR_SIZE) {
+		f2fs_msg(sb, KERN_INFO, "Invalid log sectorsize");
 		return 1;
+	}
 	if (le32_to_cpu(raw_super->log_sectors_per_block) !=
-					F2FS_LOG_SECTORS_PER_BLOCK)
+					F2FS_LOG_SECTORS_PER_BLOCK) {
+		f2fs_msg(sb, KERN_INFO, "Invalid log sectors per block");
 		return 1;
+	}
 	return 0;
 }
 
@@ -414,13 +442,16 @@ static int f2fs_fill_super(struct super_block *sb, void *data, int silent)
 		return -ENOMEM;
 
 	/* set a temporary block size */
-	if (!sb_set_blocksize(sb, F2FS_BLKSIZE))
+	if (!sb_set_blocksize(sb, F2FS_BLKSIZE)) {
+		f2fs_msg(sb, KERN_ERR, "unable to set blocksize");
 		goto free_sbi;
+	}
 
 	/* read f2fs raw super block */
 	raw_super_buf = sb_bread(sb, 0);
 	if (!raw_super_buf) {
 		err = -EIO;
+		f2fs_msg(sb, KERN_ERR, "unable to read superblock");
 		goto free_sbi;
 	}
 	raw_super = (struct f2fs_super_block *)
@@ -438,12 +469,14 @@ static int f2fs_fill_super(struct super_block *sb, void *data, int silent)
 	set_opt(sbi, POSIX_ACL);
 #endif
 	/* parse mount options */
-	if (parse_options(sbi, (char *)data))
+	if (parse_options(sb, sbi, (char *)data))
 		goto free_sb_buf;
 
 	/* sanity checking of raw super */
-	if (sanity_check_raw_super(raw_super))
+	if (sanity_check_raw_super(sb, raw_super)) {
+		f2fs_msg(sb, KERN_ERR, "Can't find a valid F2FS filesystem");
 		goto free_sb_buf;
+	}
 
 	sb->s_maxbytes = max_file_size(le32_to_cpu(raw_super->log_blocksize));
 	sb->s_max_links = F2FS_LINK_MAX;
@@ -477,18 +510,23 @@ static int f2fs_fill_super(struct super_block *sb, void *data, int silent)
 	/* get an inode for meta space */
 	sbi->meta_inode = f2fs_iget(sb, F2FS_META_INO(sbi));
 	if (IS_ERR(sbi->meta_inode)) {
+		f2fs_msg(sb, KERN_ERR, "Failed to read F2FS meta data inode");
 		err = PTR_ERR(sbi->meta_inode);
 		goto free_sb_buf;
 	}
 
 	err = get_valid_checkpoint(sbi);
-	if (err)
+	if (err) {
+		f2fs_msg(sb, KERN_ERR, "Failed to get valid F2FS checkpoint");
 		goto free_meta_inode;
+	}
 
 	/* sanity checking of checkpoint */
 	err = -EINVAL;
-	if (sanity_check_ckpt(raw_super, sbi->ckpt))
+	if (sanity_check_ckpt(raw_super, sbi->ckpt)) {
+		f2fs_msg(sb, KERN_ERR, "Invalid F2FS checkpoint");
 		goto free_cp;
+	}
 
 	sbi->total_valid_node_count =
 				le32_to_cpu(sbi->ckpt->valid_node_count);
@@ -510,17 +548,24 @@ static int f2fs_fill_super(struct super_block *sb, void *data, int silent)
 
 	/* setup f2fs internal modules */
 	err = build_segment_manager(sbi);
-	if (err)
+	if (err) {
+		f2fs_msg(sb, KERN_ERR,
+			"Failed to initialize F2FS segment manager");
 		goto free_sm;
+	}
 	err = build_node_manager(sbi);
-	if (err)
+	if (err) {
+		f2fs_msg(sb, KERN_ERR,
+			"Failed to initialize F2FS node manager");
 		goto free_nm;
+	}
 
 	build_gc_manager(sbi);
 
 	/* get an inode for node space */
 	sbi->node_inode = f2fs_iget(sb, F2FS_NODE_INO(sbi));
 	if (IS_ERR(sbi->node_inode)) {
+		f2fs_msg(sb, KERN_ERR, "Failed to read node inode");
 		err = PTR_ERR(sbi->node_inode);
 		goto free_nm;
 	}
@@ -533,6 +578,7 @@ static int f2fs_fill_super(struct super_block *sb, void *data, int silent)
 	/* read root inode and dentry */
 	root = f2fs_iget(sb, F2FS_ROOT_INO(sbi));
 	if (IS_ERR(root)) {
+		f2fs_msg(sb, KERN_ERR, "Failed to read root inode");
 		err = PTR_ERR(root);
 		goto free_node_inode;
 	}